Thematic overview
Magnetic Random Access Memories (MRAM) is a non-volatile memory technology, where information is stored by the magnetization direction of magnetic electrodes, very similar to computer hard-disk drives. The goal for MRAM memory is to simultaneously achieve high-speed read/write times, high density and unlimited cycling compared to other existing and emerging technologies.
Our group is developing advanced MRAM cell concepts patented at Spintec. The concepts are based on the use of temperature to reduce power consumption and increase the stability of the stored information. These ideas go beyond the conventional MRAM approach. The naturally occurring temperature increase during the write step is not lost, but is instead used to achieve the seemingly opposing goal of lowering the power consumption and increasing the thermal stability in the operating temperature range. Our group fosters young and experienced researchers developing/applying their expertise in the field of MRAM.
Questions to be addressed
Our main research axis is to use the naturally occurring temperature increase during the write step, when a current flows through the magnetic tunnel junction. The heating is used to go above a temperature threshold, making it possible to write the storage layer magnetization. This principle has been applied to in-plane magnetization cells using a storage layer pinned by an anti-ferromagnet and recently to perpendicular anisotropy cells. Our group’s goal is to demonstrate the proof-of-concept and then improve MRAM cell properties.
Our work involves the development of magnetic material systems, nano-fabrication (20-200nm cells), characterization of devices (magnetic & electrical) and simulation of the device behavior. Our activity in these vast fields is as follows;: On materials research, we are developing magnetic tunnel junctions with in-plane and perpendicular magnetic anisotropy. New electrode stacks having the material properties required by each specific concept need to be integrated in magnetic tunnel junctions, while achieving high levels of TMR signal. For the characterization of each concept we determine the write window parameters in terms of magnetic field, power consumption and magnetization reversal dynamics. Macrospin and micromagnetic simulation provide a better physical understanding of the system properties and the possibilities for optimization.
Projects
ANR EXCALYB – Perpendicular Anisotropy Materials for High-Density Non-volatile Magnetic Memory Cells
Crocus R&D – Thermally assisted MRAM
Samsung SGMI
Partners
Crocus Technology
Institut Néel
SP2M/NM
SAMSUNG
Applied Materials
SINGULUS
Recent news
- SPINTRONIC DEVICES FOR MEMORY AND LOGIC APPLICATIONS [July 02nd, 2015]
Spinelectronics is a very rapidly expanding area of R&D which merges magnetism and electronics (Nobel Prize 2007). Since the discovery of giant magneto-resistance (GMR) in 1988, several breakthroughs have further boosted this field [spin-valves 1990, ... - FINITE ELEMENT MODELING OF CHARGE- AND SPIN-CURRENTS IN MAGNETORESISTIVE PILLARS WITH CURRENT CROWDING EFFECTS [July 02nd, 2015]
Charge- and spin-diffusion equations, taking into account spin-diffusion and spin-transfer torque, were numerically solved using a finite element method in complex noncollinear geometry. As an illustration, this approach was used to study the spin-dependent transport ... - EXTENDED SCALABILITY AND FUNCTIONALITIES OF MRAM BASED ON THERMALLY ASSISTED WRITING [July 02nd, 2015]
A recent report from ITRS ERD/ERM working group has identified STT MRAM and RedoxRAM as the most promising candidates for emerging scalable and manufacturable non-volatile memories1. This paper is focused on MRAM. It explains how ... - THERMALLY ASSISTED MRAMS: ULTIMATE SCALABILITY AND LOGIC FUNCTIONALITIES [July 02nd, 2015]
This paper is focused on thermally assisted magnetic random access memories (TA-MRAMs). It explains how the heating produced by Joule dissipation around the tunnel barrier of magnetic tunnel junctions (MTJs) can be used advantageously to assist ... - MRAM WITH SOFT REFERENCE LAYER: IN-STACK COMBINATION OF MEMORY AND LOGIC FUNCTIONS [July 02nd, 2015]
Q. Stainer, L. Lombard, K. Mackay, R. C. Sousa, I. L. Prejbeanu, B. Dieny This paper describes an original concept of thermally assisted MRAM in which memory and logic functions are combined in the same stack. ...
SOUSA Ricardo
ricardo.sousa@cea.fr
BALTZ Vincent
vincent.baltz@cea.fr
PREJBEANU Lucian
lucian.prejbeanu@cea.fr
DIENY Bernard
bernard.dieny@cea.fr
